Haglund’s syndrome requires a distressing swelling of the inflamed retrocalcaneal bursa (a little fluid loaded sac Situated in the back of the heel), at times combined with the degeneration from the fibers of the Achilles tendon immediately at its insertion to the heel bone (insertional tendinopathy on the Achilles tendon). https://www.theorthopaedicandpainpractice.com/what-are-spurs-on-the-foot/